Tips For Specifying Linear Actuators

Pneumatic linear actuators are designed to move in a straight line and are one of the simplest, most cost-effective, and straightforward ways to accomplish linear motion.

Introduction to Linear Actuators
Linear actuators are utilized throughout the industrial sector, in factory automation, transportation, packaging, life sciences, and much more.

Pneumatic linear actuators are engineered to convert compressed air into a linear motion, most commonly with a piston rod extending and retracting, but can also be designed with a carriage that moves on the cylinder tube or guideway.

Construction and materials
Most linear actuators are constructed of aluminum, such as Parker’s P1F-S series, which is suitable for a large number of applications.

Know Your Pneumatics: Hints and Tips for Specifying Linear Actuators – P1F ISO 15552 cut away – Parker Hannifin Pneumatic Division EuropeHowever, if you’re operating in a challenging environment or one that requires washing down such as food processing and packaging, then you may require one constructed of stainless steel to prevent contaminants caused by corrosion, such as Parker’s P1S series.

In such environments, you should also consider specifying a linear actuator with excellent sealing technology to prevent contaminants from entering the cylinder.

Some offer wiper and metallic scraper options that will remove external debris and adherents from the piston rod.

Enhanced surface treatments, such as powder coatings and anodizing of the two typical pneumatic cylinder materials (aluminum and steel) can also protect against contamination in caustic washdown environments.

Operating the cylinder
Linear actuators can be specified in a variety of different bore and stroke lengths giving a range of speeds and forces so you can achieve the required movement.

They can also be specified as single-acting (single port to allow compressed air to enter the cylinder to move the piston to the desired position) or double-acting (port at each end to move the piston forward and back by alternating the port that receives the air pressure) such as Parker’s P1D-T Large Bore series.

Typically, the body of the actuator is connected to a support frame and the end of the piston rod is connected to the element of the machine that needs to be moved. A control valve directs compressed air into the extended port while opening (exhausting) the retract port.

Actuators are at the working end of a system, working alongside filters, pressure regulators, lubricators, control valves, and flow controls all fed by a compressor. These components are connected together via piping or tubing and fittings.

Specifying a linear actuator
Typical questions to ask when specifying a linear actuator are:
What are you using it for?

What environment are you using it in?

How much force do you need?

How far does it need to travel, how many strokes do you need?

How fast does it need to move?

How often should the movement be achieved?